Hello everyone! This is my first topic here, so I am not sure if I am doing this correctly. But I want to ask 2 questions:

I already have 2 arduino, 1 Uno (Rev3 I gess) and a Arduino Nano V3.0 but I'm thinking about going to Stand-alone Arduino. And I have searched and found some things, but I am not sure if I get it correctly. I have seen this (http://arduino.cc/en/Tutorial/ArduinoToBreadboard) and I'm interessted in the Minimal Configuration Part. Can I connect the ATmega328 without any other component and program it like that (preferable using another arduino as ISP and a Bootloader Burner)? And to power the chip, can I use an Power Adapter with these caracteristics (Input: Ac 110V -240V 50160HZ; Output: DC 5V±0.2V DC 500mA±30mA) without a voltage regulator or is better another thing?

By the way, what I want to do in the end is to use a NRF24L01 2.4GHz Wireless Transceiver Module to talk between different boards to controll some lights, push buttons and motors. Can be done with that? (I gess after all this was 3 quesitons

Thank you in advance for your time and sorry for any mistake, english in not my native language.

As already said, just ensure that it is a regulated power supply and not an unregulated one, or you could exceeee the 6v maximum for the standalone chip, and possibly have issues with any measurements taken on the analogue pins as Vcc changes.

As for the nRF24L01, they will do what you want very nicely and inexpensively. One thing you MUST ensure though, is that you are using the nRF24L01+. That + is a big factor as the non + will not tolerate 5v power. The non + require 3.3v for power. The + model can take 5v.

As for the nRF24L01, they will do what you want very nicely and inexpensively. One thing you MUST ensure though, is that you are using the nRF24L01+. That + is a big factor as the non + will not tolerate 5v power. The non + require 3.3v for power. The + model can take 5v.

Alternatively, why not run the atmega328p at 3.3V instead of 5V?

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The first question was about running from a 5v power supply that the OP has already, and 16Mhz @ 3.3v would be overclocking. Not everyone is comfortable with running out of spec as it could be at the cost of stability at a later date.

He could also use a 3.3 VR but, tbh, most of the nRF modules are the plus now even if they are not described as such.

The first question was about running from a 5v power supply that the OP has already, and 16Mhz @ 3.3v would be overclocking. Not everyone is comfortable with running out of spec as it could be at the cost of stability at a later date.

It was also about running with no external components. So he must be using the internal oscillator, which means he's running at about 8MHz or less - well within spec @ 3.3V.

Formal verification of safety-critical software, software development, and electronic design and prototyping. See http://www.eschertech.com. Please do not ask for unpaid help via PM, use the forum.

The SPI speeds are derived from the system clock speed so the choices will all be half the speed of what you would get with a 16 MHz clock.

Since SPI has separate data and clock there isn't the same sensitivity to clock speed that asynchronous serial communication has. It should work even with wildly varying clock speeds.

I knew that running the ATmega without the 16mhz crystal it would be slower, but it also means that the Delay time will be different?By the way, I have 3 of that crystals, they are really needed, I mean, I should use them or for this specific case I can leave the ATmega without it?

As for the nRF24L01, they will do what you want very nicely and inexpensively. One thing you MUST ensure though, is that you are using the nRF24L01+. That + is a big factor as the non + will not tolerate 5v power. The non + require 3.3v for power. The + model can take 5v.

Mine are the + model by the way when I bought them I didn't notice that. In fact, I thought it was a part of the name, and it doesn't matter for anything x)

Yes, but you don't need a bootloader if you are programming the chip via ICSP.

I had already thing about that, but I didn't find many things on that programming method and I don't know practically anything about that programming language

Writing the program is the same whether you use a bootloader or program the chip directly through ICSP. To use ICSP, you connect your programmer and use the "Upload using programmer" function in the Arduino IDE instead of plain "Upload".

Because I didn't find any 3.3V power source, and I've read somewere (don't remember where exactly) that the ATmega chip must be at 5V to work correctly. It isn't true?

The atmega328p can use anything between 1.8V and 5V. The maximum clock speed that is guaranteed to work varies with voltage, from 4MHz @ 1.8V to 20MHz @ 4.5V and higher. But if your peripherals can run from 5V, then you may as well use 5V.

By the way, I have 3 of that crystals, they are really needed, I mean, I should use them or for this specific case I can leave the ATmega without it?

If you need accurate timing, use the crystal. If you can accept some variation (e.g. +/-10% if you don't calibrate the internal oscillator, better if you are prepared to calibrate it), then you don't need to use a crystal. If you decide to use a bootloader, then you will either need a crystal or ceramic resonator, or you will have to calibrate the internal clock (unless you are lucky).

Formal verification of safety-critical software, software development, and electronic design and prototyping. See http://www.eschertech.com. Please do not ask for unpaid help via PM, use the forum.

If you need accurate timing, use the crystal. If you can accept some variation (e.g. +/-10% if you don't calibrate the internal oscillator, better if you are prepared to calibrate it), then you don't need to use a crystal. If you decide to use a bootloader, then you will either need a crystal or ceramic resonator, or you will have to calibrate the internal clock (unless you are lucky).

I don't have any idea how to calibrate the internal clock you said that is the same programming with or without the bootloader, so if I use ICSP, I will not need to calibrate the internal clock, since I do not need accurate time , is that it?

The atmega328p can use anything between 1.8V and 5V. The maximum clock speed that is guaranteed to work varies with voltage, from 4MHz @ 1.8V to 20MHz @ 4.5V and higher. But if your peripherals can run from 5V, then you may as well use 5V.

So I should look for a power supply with less voltage, or use a voltage regulator to bring down the 5V to 3.3V?And I can use the nRF24L01+ with only 3.3, or it must be the one that doesn't have the "+"?